Which are the different corrosion classes

As per the ISO 12944-2:2017 standard

  • C1 – very low
    • Heated buildings with healthy atmosphere. E.g.: offices, shops, schools, hotels.
  • C2 – low 
    • Atmosphere with a low pollution level. E.g.: rural areas.
    • Non-heated buildings with possible occurrence of condensation. E.g.: depots, sports halls.
  • C3 – medium 
    • Urban and industrial atmospheres, moderate sulphur dioxide pollution. E.g.: coastal area with low salinity.
    • Production rooms with high humidity and some air pollution. E.g.: breweries, laundries, food-processing plants.
  • C4 – high 
    • Industrial areas and coastal areas with moderate salinity. E.g.: chemical plants, swimming pools.
  • C5 – very high 
    • Industrial areas and coastal areas with high humidity and aggressive atmosphere, coastal areas with high salinity.
    • Buildings or areas with almost permanent condensation and high pollution.
  • CX – extreme 
    • Offshore areas with high salinity and industrial areas with extreme humidity, aggressive atmosphere and sub-tropical and tropical atmospheres.
    • Industrial areas with extreme humidity and aggressive atmosphere.
  • Im1 – immersion in fresh water
    • Structures in rivers (dams), hydroelectric power stations.
  • Im2 – immersion in sea or brackish water without cathodic protection
    • Immersed structures without cathodic protection. E.g.: port zones with structures. E.g.: lock valves, landing stages.
  • Im3 – burial in soil
    • Cisterns buried in the ground, pipes and steel piles.
  • Im4 – immersion in sea or brackish water with cathodic protection
    • Structures immersed into water, with cathodic protection. E.g.:  offshore structures

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